Hackers based in China appear to have launched a "coordinated, covert and targeted" campaign of cyber espionage against a number of prominent Western energy firms.
According to a McAfee report cited by the Wall Street Journal, the hacking incidents - dubbed "Night Dragon" - may have begun as early as 2007 and are still ongoing.
The hackers routinely managed to scrape gigabytes of sensitive data about oil- and gas-field ops, project financing and bidding documents.
"We saw no evidence of sabotage activities in these attacks. These individuals almost seemed like company worker bees. They operated on a strict weekdays, nine-to-five Beijing time-zone schedule," McAfee VP Dmitri Alperovitch told the WSJ.
"The facts point to Chinese hacker activity that is organized, so [it is] potentially directed either by the private sector or the public sector. But it's impossible for me to know for sure which one."
Unsurprisingly, Chinese embassy spokesperson Wang Baodong noted that past allegations about Sino-based hacking had been raised "unfairly."
"China has very strict laws against hacking activities, and China is also a victim of such activity," he insisted.